Known in the art is a flow-rate controller (U.S. Pat. No. 3,130,747, Cl. 137-504, 1964) comprising a spring-loaded slide valve communicating with the inlet space of the unit from one side, and with the internal space of the controller through openings in the slide valve from the other side. This controller assumed to be similar to the present invention is deficient in that it is designed for operation under constant flow rate conditions and cannot assure the manifold operation in different modes.
Prior art also includes a liquid flow-rate controller which is made in the form of a casing with the main inlet and outlet branch pipes and comprises: a stationary front guide bush with front orifices and with a lateral partition limiting the internal space of said bush to form an inlet space communicating directly with the main branch pipe; a sleeve arranged coaxially in said front guide bush and caused by a mechanically connected actuator to slide therein with a possibility of covering the front orifices; a stationary rear guide bush located in line with the front guide bush and having outlet orifices in its walls; a piston-type slide valve with skirt arranged between said lateral partition and said rear guide bush to form a piston space limited by said lateral partition, the piston being spring-loaded on the side of the rear guide bush and capable of making contact with said lateral partition; a passage space formed between the casing and said front and rear guide bushes whereby the inlet space communicates with the outlet branch pipe via the front and outlet orifices. The holes provided in the aforesaid piston skirt enable the skirt cavity to communicate with the passage space, and the rear portion of the skirt which is a free fit on the rear guide bush can cover the latter's outlet orifices ("Cosmonautics" Encyclopedia, Sovetskaya encyclopedia, 1985, p. 16, FIG. 9).
The disadvantage of this controller which represents the closest prior art of the claimed invention consists in that the rate of liquid flow through the gaps between the controller parts at further reduction of the minimal flow rate becomes commensurate with the rate of liquid flow through the throttling device, wherefore the accuracy in the setting of the required flow rate diminishes appreciably, particularly at the low power setting, which is of special importance in the engine starting mode.
Besides, the known controller calls for special devices making it possible to change the engine fuel supply from an additional inlet branch pipe (the starting tank) to the main inlet branch pipe (main fuel manifold).